CHICAGO — With a hunger to reclaim the governor's office, Republican voters set out Tuesday to shake up Illinois' Democratic-dominated political order, energized by candidates' talk of taking on unions, unseating "career politicians" and righting the state's troubled finances.

The talk at polling stations from the Chicago suburbs in the north to the St. Louis suburbs in the southwest was of reversing the state's indebtedness and keeping businesses and jobs from leaving Illinois. Describing their desire for change, people used phrases like "break the system."

To many, the governor's race was shaping up as a potentially transformative battle over union influence, with some voters saying they want to break an alliance between organized labor and longtime Democratic politicians in control of the governor's mansion and the Legislature.

Organized labor was battling back out of concern that the leading Republican candidate, multimillionaire venture capitalist Bruce Rauner, could seek to weaken unions in the same way GOP governors have in other states across the Midwest.

"It's hard to make true progress when there's a union ... when you have a union rep always in the middle of things," said Veronique Escalante, 40, a consultant from the western Chicago suburb of Glen Ellyn who voted for Rauner.

Rauner, who has never held public office but leads the four-person Republican field after spending millions on his campaign, says he would model his governorship after those of Wisconsin Gov. Scott Walker and former Indiana Gov. Mitch Daniels. Both significantly rolled back union power in their states in what they said were necessary steps to attract businesses and reduce costs. Rauner faces three longtime lawmakers for the nomination: state Sens. Bill Brady and Kirk Dillard, and state Treasurer Dan Rutherford.

"Rauner is going to be a bull in a china shop; we need a bull," said Tom Sommer, a 57-year-old real estate broker from the southwest Chicago suburb of Hinsdale. "It's not going to be more of the same."

Issues such as a public pension overhaul and high taxes "are coming to the fore and the old guard is not going to handle that," Sommer said, adding that he voted for Rauner because of his tough talk against the unions that represent public sector workers. That sentiment persists despite Democratic Gov. Pat Quinn's push to right Illinois' finances by overhauling the heavily underwater public pension systems, which earned him the unions' ire.

Rauner has also won supporters with his call for term limits.

Union leaders, meanwhile, sought Rauner's defeat by encouraging members to pull Republican primary ballots and vote for Dillard, who picked up endorsements by three of the state's largest public-employee unions.

The typically left-leaning unions spent more than $6 million on the GOP primary, both in anti-Rauner and pro-Dillard ads. Rauner raised more than $14 million, including $6 million of his own money - more than any candidate seeking a gubernatorial nomination in state history.

Page 2 of 3 - In stops statewide Monday, Rauner warned supporters about the unions' efforts, saying Quinn's "allies" were trying to hijack the election. He also said legislative term limits could break the labor-Democratic alliance.

"We're going to change their world, and they know it," Rauner, of Winnetka, said during in the southern Illinois community of Herrin.

Republicans haven't held the Illinois governor's office since 2003 when Democrat Rod Blagojevich — now in prison for corruption — took office, and Democrats have almost total control of other statewide offices and the Illinois House and Senate.

In the southern Illinois city of Godfrey, voters had another reason to want to upend the state's political order, saying they felt marginalized and neglected by a political balance weighted toward Democrats and the Chicago region, the most populous part of Illinois.

"In the last 10 years, things have gotten really bad (in the state)," said Marty Johns, 48, an accountant from Godfrey. "Throw out all the Democrats in Chicago. All of our money goes up there while southern Illinois gets the crumbs."

Johns said he voted for Dillard with one primary goal: "I'm just trying to remove Quinn."

But others said they liked Quinn, whose administration has avoided major scandals — unlike his two predecessors who went to prison.

"I think he's honest and he does the best he can do with what he's got to work with," said Ed Kline, a 61-year-old LeRoy farmer who voted for Quinn. He called Rauner "the big-money guy from Chicago."

Quinn, who was Blagojevich's lieutenant governor and assumed the office after his boss was booted amid a corruption scandal, was facing lesser-known challenger Tio Hardiman in Tuesday's primary. Quinn, seeking his second full term, was expected to easily win the Democratic nomination.

Brady narrowly won the GOP nomination in 2010, but lost to Quinn in the general election. The Bloomington lawmaker said he built the support and name recognition during that bid to defeat Quinn this time around.

Married couple Carrie O'Rourke, 52, and her husband, farmer Brian O'Rourke, said they wanted Brady to win last time around and didn't like Rauner's television ads.

"I don't like a race that has been bought," Carrie O'Rourke said, adding that the ads "were nasty."

Rutherford, of Chenoa, has done little campaigning recently. He's all but conceded defeat after a former employee filed a federal lawsuit accusing Rutherford of sexually harassing him and political coercion. Rutherford denied the allegations, saying they were politically motivated.

Voters also will choose between two Republicans vying to take on U.S. Sen. Dick Durbin, the Senate's second-ranking Democrat, in the fall. That primary pits dairy magnate and state Sen. Jim Oberweis, who has lost five of his six bids for public office, against political newcomer and West Point graduate Doug Truax.

Page 3 of 3 - Also on the ballot are primary races for the U.S. House, Illinois Legislature, statewide constitutional officers and local offices.